Comes sweeping into it; and thus, while all the muddy deposit of the rivers is swept away, the malaria is at the same time removed, and by this means the city enjoys so good a sanitary reputation that the government has fixed on it as a place for the reception and training of gladiators."
Then, turning his attention to the malaria of birds, he worked out the life-history of these cells within the body of the mosquito.
Maria di Porto erected in the town in the 16th century (owing to malaria, as in the case of those of Classe), and of S.
MALARIA, an Italian colloquial word (from mala, bad, and aria, air), introduced into English medical literature by Macculloch (1827) as a substitute for the more restricted terms "marsh miasm" or "paludal poison."
Demonstrated by a series of accurate investigations, contributed by many workers, that malaria is caused by a microscopic parasite in the blood, into which it is introduced by the bites of certain species of mosquito.
An old popular belief current in different countries, and derived from common observation, connected mosquitoes with malaria, and from time to time this theory found support in more scientific quarters on general grounds, but it lacked demonstration and attracted little attention.
Following up this line of investigation, Major Ronald Ross in 1895 found that if a mosquito sucked blood containing the parasites they soon began to throw out flagellae, which broke away and became free; and in 1897 he discovered peculiar pigmented cells, which afterwards turned out to be the parasites of aestivo-autumnal malaria in an early stage of development, within the stomachwall of mosquitoes which had been fed on malarial blood.
The disseminators of malaria are exclusively Anophelinae, but even among these it is only certain species that are dangerous, since the others appear to be incapable of acting as hosts of the parasites.
The mortality from malaria in 1902 was higher than for any other part of Italy-1037 persons, or 154 per 100,000 (Basilicata, 141; Apulia, 104; Calabria, 77; Sicily, 76; province of Rome, 27).
It is subject, however, to extreme and rapid variations in temperature, to alternations of dry and humid winds (the latter, called catias, being irritating and oppressive), to chilling night mists brought up from the coast by the westerly winds, and to other influences productive of malaria, catarrh, fevers, bilious disorders and rheumatism.
Yet in some Tusban provinces, as, for instance, that of Grosseto, where malaria rages, laborers are organized in gangs under corporals, who undertake harvest work.
But probably the greater part of the enormous total of deaths set down to malaria is due to the malarial cachexia.
With regard to the parasites, which are the actual cause of malaria in man, an account of them is given under the heading of Parasitic Diseases, and little need be said about them here.
The drug is not a true specific, as quinine is for malaria, since it rarely, if ever, prevents the cardiac damage usually done by rheumatic fever; but it entirely removes the agonizing pain, shortly after its administration, and, an hour or two later, brings down the temperature to normal.
The discovery of the parasite of malaria by Laveran, and of the method by which it gains entrance to the human body, through the bite of a particular variety of mosquito, by Manson and Ross, promises much in the way of eradication of the disease in the future.
Of Tuscany (1822-1844) made the first successful efforts to counteract the malaria which has affected the district, by drainage, the filling up of swamps, and the establishment of new farms, and since his time continuous efforts have been made with considerable success.
Unfortunately several of these fertile tracts suffer severely from malaria (q.v.), and especially the great plain adjoining the Gulf of Tarentum, which in the early ages of history was surrounded by a girdle of Greek cities—some of which attained to almost unexampled prosperity—has for centuries past been given up to almost complete desolation.
The city of Panama was formerly a stronghold of yellow fever and malaria, which American sanitary measures have practically eradicated.
As a refuge from the malaria, which prevailed at Classe itself, with fine 17th-century cloisters, contains the important museum, which has Roman and Byzantine antiquities, inscriptions, sculptures, jewelry, &c. - including the possible remains of a suit of gold armour of Theodoric - and a collection of Italian woodcuts; also the library with rare MSS.
The subject has a special interest for Italy, which is devastated by malaria, and Italian science has contributed materially to the solution of the problem.
To apply these discoveries to the malaria of man was an obvious step. In working out the details the Italian school have again taken a prominent part.
Thus we get a complete scientific demonstration of the causation of malaria in three stages: (1) the discovery of the parasite by Laveran; (2) its life-history in the human host and connexion with the fever demonstrated by the Italian observers; (3) its life-history in the alternate host, and the identification of the latter with a particular species of mosquito by Ross and Manson.
In 1898 it was conclusively shown in Italy that if a mosquito E of the Anopheles variety bites a person suffering from malaria, and is kept long enough for the parasite to develop in the salivary gland, and is then allowed to bite a healthy person, the latter will in due time develop malaria.
Mosquitoes caught by the experimenters, and sent to London, produced malaria in persons who submitted themselves to the bites of these insects at the London School of Tropical Medicine.
Of 24 protected persons, all escaped but four, and these had to be out at night or otherwise neglected precautions; of 38 unprotected persons, all contracted malaria except two, who had apparently acquired immunity.
The result was that the houses were free from mosquitoes and no malaria occurred throughout the entire season, though there had been 40 cases in the previous year.
For instance, the swampy character of malarial areas is explained by their breeding in stagnant water; the effect of drainage, and the general immunity of high-lying, dry localities, by the lack of breeding facilities; the danger of the night air, by their nocturnal habits; the comparative immunity of the upper storeys of houses, by the fact that they fly low; the confinement of malaria to well-marked areas and the diminution of danger with distance, by their habit of clinging to the breeding-grounds and not flying far.
Similarly, the subsidence of malaria during cold weather and its seasonal prevalence find an adequate explanation in the conditions governing insect life.
The species best known in connexion with malaria are A.
The most important question raised by the mosquitoparasitic theory of malaria is that of prevention.
(2) Much attention has been directed in scientific circles to the possibility of "stamping out" epidemic malaria by administrative measures.
Melanine particles formed in the spleen in malaria, which pass along with the blood through the liver, are appropriated by the endothelial cells of the hepatic capillaries, and are found embedded within their substance.
The city of Rome is an example of what can be done by drainage; situated in the midst of malaria, it is itself quite healthy.
In spite of the difficulties, however, there is no doubt that a great deal can be done to reduce, if not stamp out, malaria by the methods indicated, which should be applied according to circumstances.
An encouraging example is afforded by the remarkable fact that malaria, which was once rife in certain districts of England, has now died out, although the Anopheles maculipennis mosquito still exists there.
- Celli, Malaria; Christy, Mosquitoes and Malaria; Manson, Tropical Diseases; Allbutt's System of Medicine; Ross, "Malaria," Quain's Dictionary of Medicine, 3rd ed.; The Practitioner, March, 1901 (Malaria Number); Lancet (Sept.